Unfair Dice - Ivars Peterson (MathTrek)
Dice represent an intriguing example of the interplay between randomness, chance, and physical law. The simplest mathematical model of a standard die is based on the assumption that the die is a perfect cube. A cube has six faces, and each face has an
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Unfolding Orbifolds - Heidi Burgiel; The Geometry Center
A study of how a pattern can be reconstructed from an orbifold, using both hands-on exploration and the computer program TesselMania!. These activities are a good introduction to the movie Shape of Space. From Math 5337, Technology in the Geometry Classroom,
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The Uniform Polyhedra - Roman Maeder
A shortened version of the notebook Polyhedra.ma from Illustrated Mathematics [Gloor/Amrhein/Maeder95]. Uniform polyhedra have regular faces and congruent vertices. Allowing for non-convex faces and vertex figures, there are 75 such polyhedra, as well
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Unifpack (Web version 2.0) - Carlos O'Ryan Lira
A set of programs and C libraries for studying Riemann Surfaces with symmetry. Unifpack accepts a presentation of a finite group and calculates the Cayley graph of the group for that presentation. If the presentation is "admissible," Unifpack can calculate
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Union of Bulgarian Mathematicians (UBM)
A voluntary, creative, non-political organisation whose purpose is to bring together people who are interested in Mathematics and Computer science or are involved in activities related to those fields. Contact info, meetings.
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UnitConversion.org
Perform online unit conversions for volume, distance, temperature, time, speed, and more for a total of 2,100 kinds of units in 78 different categories.
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Unit Converter
The converter works for units of area, energy, pressure, volume,
temperature, mass, length, numbers, velocity etc. You put in a number and
select a base unit and select a unit to convert to. The conversion result
will immediately appear in the output
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The Units of Measure C++ Library - Keith Nicewarner
The purpose of this library is to try to make it more difficult to make
coding mistakes that incorrectly mix units of measure. This is done with a
set of C++ classes that provide type-safe manipulation of units of measure
for various properties.
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Units of Measurement for Ada - Dmitry A. Kazakov
Public domain software for dealing with physical measurement units. The library provides physically correct unit arithmetic and tools for input and output of units, which including support of various irregular units. As an illustrative example a platform-independent
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The Universe of Discourse - Mark Dominus
Blog by the perl programmer who authored the book Higher-Order Perl and columns for The Perl Journal. Posts, which date back to November, 2005, have included "Fibonacci-like sequences," "More Liber Abaci," "The 3n+1 domain," "Biblical infallibility and
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Untangled - Mehta, Gayatri; Luo, Xiaozhong; et al.
Map and place logic blocks in this game to make more compact circuit layouts on a grid -- and more efficient computer chips. Visually appealing graphs bring nodes closer to parents or children and untangle knots in graphs; behind the scenes, the accumulated
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US2020
By organizing a million mentors from industry, this organization hopes to provide "uplifting moments of discovery to children through real-world, hands-on projects and academic coaching" in science, technology, engineering and math (STEM) fields. The
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USAMO/APMO/IMO/Putnam Archive - Kiran S. Kedlaya
Questions from some recent math competitions, in LaTeX or postscript format: the USA Mathematical Olympiad (USAMO) for high school students [1989-1999]; the Asian Pacific Mathematical Olympiad (APMO), a regional olympiad among countries on the Pacific
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U.S. Census Bureau
Information (searchable by keyword and browseable by subject) from summary data files across cities, towns, counties, states, and other geographic and demographic boundaries, useful for many purposes from allocating representation in legislative bodies
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U.S. Energy Information Administration (EIA)
Links to facts/statistics on energy topics from A to Z: acid rain and air conditioning to world energy data on coal consumption, electricity prices, natural gas and oil consumption, and more. With tables, graphs, articles (some in PDF format), a Windows
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The Valuation Theory Home Page - Franz-Viktor Kuhlmann
A forum for all mathematicians who work in valuation theory or apply valuation theoretical results in their own field of research. The home page offers: information about conferences and special events; names and email addresses of mathematicians working
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